System and Method to Provide Verification during a Fishing Operation in a Wellbore

ABSTRACT

A technique provides a system and method to verify attachment of a fishing tool with a downhole well tool. The fishing tool comprises a latching mechanism that latches onto the well tool to be retrieved. The fishing tool also comprises a detection device to verify connection of the latching mechanism. The detection device provides a signal uphole to verify attachment to the well tool.

BACKGROUND

In a variety of well related operations, tools are used to carry out desired tasks at downhole locations. For example, different types of tools are used to drill wellbores, to deploy tubing and other equipment downhole, to perform testing operations, and to conduct servicing operations. During these operations, a tool occasionally becomes stuck in the wellbore or disconnected from its conveyance. If the tool is stuck in the wellbore, the tool can be cut free to enable retrieval of the conveyance and other downhole equipment.

To retrieve the tool left downhole, a fishing operation is conducted in which a fishing tool is deployed downhole from a surface rig. The fishing tool comprises a latching or attachment end designed to engage the tool, i.e. fish, to be retrieved. However, attachment of the fish can occur deep within the wellbore which makes it difficult to determine whether the fishing tool has contacted and adequately engaged the fish. Many hours of rig time can be wasted in withdrawing the fishing tool to discover the fishing expedition was not successful.

SUMMARY

In general, the present invention provides a system and method to verify attachment of a fishing tool with a fish. The fishing tool comprises a latching mechanism to latch onto the fish to be retrieved and a detection device to verify connection of the latching mechanism. The detection device provides a signal uphole to verify attachment of the fish.

BRIEF DESCRIPTION OF THE DRAWINGS

Certain embodiments of the invention will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements, and:

FIG. 1 is a front elevation view of a fishing tool system being deployed into a wellbore, according to an embodiment of the present invention;

FIG. 2 is a front elevation view similar to that of FIG. 1 but showing the fishing tool engaged with a fish, according to an embodiment of the present invention;

FIG. 3 is a front elevation view similar to that of FIG. 1 and also showing a communication system for communicating signals uphole, according to an embodiment of the present invention; and

FIG. 4 is a front elevation view showing an alternate communication system, according to an alternate embodiment of the present invention.

DETAILED DESCRIPTION

In the following description, numerous details are set forth to provide an understanding of the present invention. However, it will be understood by those of ordinary skill in the art that the present invention may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible.

The present invention relates to a system and methodology for performing a fishing operation. The system and methodology are used to provide an indicator as to when a well tool, i.e. fish, is engaged with the fishing tool. The indicator may be in the form of a signal provided uphole when the fishing tool is engaged with the fish. The signal also can be continually provided uphole while the fish is pulled from the well to inform an operator that the fish remains attached to the fishing tool. The ability to provide this indication to an operator helps avoid withdrawal of the fishing tool without the fish being attached, thus preventing wasted rig time.

In one embodiment, a fishing tool is deployed downhole into a wellbore via a conveyance, such as a coiled tubing fishing tool conveyance. However, other types of conveyances, including drill string, wireline and other conveyance mechanisms, can be used. The fishing tool usually is deployed downhole through a tubing, such as a casing or a production tubing positioned within the casing. The fishing tool comprises a latching mechanism for engaging and gripping the fish and a cooperating detection device that is able to provide, e.g. transmit, a signal uphole indicating the latching mechanism has engaged or latched onto the fish. A signal can be sent uphole to an operator to indicate full engagement of the fishing tool with the fish, and this signal also can be provided during withdrawal of the fish to indicate continued attachment of the fish to the fishing tool. Depending on the type of detection device used, the signal can be an individual signal, a constant signal, or an intermittent signal.

Referring generally to in FIG. 1, one example of a well system 20 is illustrated according to an embodiment of the present invention. In this example, well system 20 comprises a fishing tool 22 that is being delivered downhole into a well via a conveyance 24, such as a coiled tubing conveyance or other suitable conveyance. The fishing tool 22 is moved downhole towards a well tool 26, i.e. fish, which is to be retrieved.

The fishing tool 22 is moved downwardly along a wellbore 28 and often down through a tubing 30, such as a well casing. In other applications, tubing 30 may comprise production tubing or other tubing positioned in wellbore 28, often within a surrounding casing. Fishing tool 22 is appropriately sized for movement through the tubing as necessary for a given application. As illustrated in FIG. 1, wellbore 28 extends down from surface equipment 32 positioned at a surface location 34. Surface equipment 32 may comprise a rig for deploying fishing tool 22 and conveyance 24.

In the embodiment illustrated, fishing tool 22 comprises a latching mechanism 36 designed for attachment with fish 26 when moved into engagement with fish 26, as illustrated in FIG. 2. The design of latching mechanism 36 can vary according to the application and according to the type of well tool/fish to be retrieved within wellbore 28. For example, latching mechanism 36 can be designed to engage the fish 26 internally or externally. Additionally, latching mechanism 36 may have various configurations and components that allow fishing tool 22 to be latched onto specific types of well tools.

Fishing tool 22 further comprises a detection device 38 positioned to detect when fishing tool 22 has latched onto fish 26 and to provide an appropriate signal uphole indicating the attachment. By way of example, detection device 38 may comprise a switch 40, such as a contact switch, appropriately positioned so that it is automatically switched upon full engagement of fishing tool 22 with fish 26. The detection device 38 is then able to output a signal uphole indicating fishing tool 22 has been latched onto fish 26. By way of example, the detection device 38 may be a powered device able to output the signal, or the detection device 38 can simply be used to complete a circuit that extends uphole to the surface location 34.

In the embodiment illustrated in FIG. 3, for example, fishing tool 22 is a “smart” tool coupled with a surface display system 42 via a communication line 44. Surface display system 42 may be part of an overall control system utilized in conducting the fishing operation. According to one example, communication line 44 is a hardwired line designed to carry signals from detection device 38 to display system 42. For example, communication line 44 may comprise an electrical line for carrying an electrical signal uphole from detection device 38. Alternatively, communication line 44 may comprise an optical fiber or optical communication line able to carry optical signals uphole from detection device 38. The hardwired communication line 44 can be routed along conveyance 24. If conveyance 24 comprises a coiled tubing conveyance, the communication line 44 can be secured along the coiled tubing or routed within a wall of the coiled tubing. In other applications, communication line 44 may comprise a wireless communication line.

Regardless of the specific type of communication line 44, detection device 38 may be a constant signal device able to output or convey a constant signal to display system 42 while fishing tool 22 is attached to fish 26. By way of example, detection device 38 may comprise contact switch 40 that is switched upon full engagement of the fishing tool 22 with the fish 26 to enable transmission of a constant signal during the attachment. Thus, an operator is provided with an indication that the fish 26 remains attached during the entire retrieval process as the fish is withdrawn from wellbore 28.

In alternate embodiments, the detection device 38 may be of a design that enables output of the signal only upon initial engagement of fishing tool 22 with fish 26. Other designs enable the detection device 38 to provide periodic or intermittent signals uphole indicating retention of the fish 26. This latter approach can be useful when the fishing tool 22 is not a smart tool and does not have an electrical line or fiber-optic cable extending to the surface.

As illustrated in FIG. 4, for example, detection device 38 may comprise a pressure device able to output an individual or multiple pressure pulses that do not require a hardwired communication line extending between the fishing tool 22 and the surface. The pressure pulses are delivered uphole along an interior of conveyance 24, as indicated by arrows 46, or along an annulus surrounding conveyance 24, as indicated by arrows 48. By way of example, this embodiment of detection device 38 may comprise a valve 50 that actuates to provide a pressure response upon engagement of the fishing tool 22 with the fish 26. The valve 50 may be a pressure inducing or pressure indicating valve actuated mechanically upon engagement of the fishing tool 22 with the fish 26, or the valve 50 can be actuated by another source of energy. For example, valve 50 can comprise a solenoid actuated valve or otherwise actuated valve that is activated upon attachment of the fish 26.

The system and methodology can be used to provide an operator with better information during a fishing operation. Knowledge of the status of the well tool fished from a downhole location enables more consistent and efficient fishing operations. It should be noted that the specific size, configuration and components of the fishing tool 22 can vary according to the environment and according to the type of tool that is to be fished from the wellbore. Furthermore, the configuration of the detection device also can vary according to the desired signal output, available communication lines, environment, and other factors that affect the overall operation.

Accordingly, although only a few embodiments of the present invention have been described in detail above, those of ordinary skill in the art will readily appreciate that many modifications are possible without materially departing from the teachings of this invention. Such modifications are intended to be included within the scope of this invention as defined in the claims. 

1. A method for use during a fishing operation in a well, comprising: deploying a fishing tool downhole into a wellbore; attaching the fishing tool to a fish; and transmitting a signal uphole during retrieval of the fish to indicate retention of the fish by the fishing tool.
 2. The method as recited in claim 1, wherein transmitting comprises transmitting an electrical signal uphole to a receiver.
 3. The method as recited in claim 1, wherein transmitting comprises transmitting an optical signal uphole to a receiver.
 4. The method as recited in claim 1, wherein transmitting comprises transmitting a pressure signal uphole to a receiver.
 5. The method as recited in claim 1, wherein transmitting comprises transmitting during the entire fishing operation until the fish is retrieved at the surface.
 6. The method as recited in claim 1, further comprising utilizing a switch to determine engagement of the fishing tool with the fish.
 7. The method as recited in claim 1, wherein utilizing the switch comprises utilizing a contact switch that provides a constant signal when the fish is attached to the fishing tool.
 8. The method as recited in claim 1, wherein transmitting comprises using a pressure indicating valve to provide a pressure response when the fish is engaged by the fishing tool.
 9. A device, comprising: a fishing tool for use in retrieving a fish from a wellbore, the fishing tool comprising: a latching mechanism for latching onto the fish; and a detection device cooperating with the latching mechanism to enable transmission of a signal uphole indicating the latching mechanism is latched onto the fish.
 10. The device as recited in claim 9, wherein the detection device comprises a switch.
 11. The device as recited in claim 9, wherein the detection device comprises a contact switch.
 12. The device as recited in claim 9, wherein the detection device comprises a valve that provides a pressure response when the latching mechanism is latched onto the fish.
 13. The device as recited in claim 9, wherein the detection device comprises a constant signal device to output a constant signal uphole while the fish is attached to the latching mechanism.
 14. A method, comprising: connecting a fishing tool to a fishing tool conveyance; coupling a communication line between a surface location and a detection device of the fishing tool; positioning the detection device to detect attachment of a fish to the fishing tool; and providing a signal uphole through the communication line when the detection device detects attachment of the fish.
 15. The method as recited in claim 14, further comprising moving the fishing tool downhole through a tubing.
 16. The method as recited in claim 14, wherein connecting comprises connecting the fishing tool to a coiled tubing conveyance.
 17. The method as recited in claim 14, wherein coupling comprises coupling an electrical communication line between the surface location and the detection device.
 18. The method as recited in claim 14, wherein coupling comprises coupling a fiber optic communication line between the surface location and the detection device.
 19. The method as recited in claim 14, wherein coupling comprises coupling a wireless communication line between the surface location and the detection device.
 20. The method as recited in claim 16, wherein coupling comprises routing the communication line within a wall of the coiled tubing conveyance.
 21. The method as recited in claim 14, wherein positioning comprises positioning a contact switch to detect attachment of the fish.
 22. A system, comprising: a coiled tubing conveyance; and a fishing tool coupled to the coiled tubing conveyance, the fishing tool comprising: a latching mechanism; and a detection device to detect attachment of the latching mechanism to a fish.
 23. The system as recited in claim 22, further comprising a communication line routed along the coiled tubing conveyance to carry a signal uphole when the latching mechanism is attached to the fish.
 24. The system as recited in claim 23, wherein the detection device outputs a constant signal when the fish is attached.
 25. The system as recited in claim 22, wherein the detection device outputs a pressure signal when the fish is attached. 